Update HammingDistanceTest.java

Author: TusharNaugain

src/test/java/com/thealgorithms/strings/HammingDistanceTest.java

@@ -1,69 +1,64 @@
 package com.thealgorithms.strings;
 
-import static org.junit.jupiter.api.Assertions.*;
-import org.junit.jupiter.api.*;
-import org.junit.jupiter.params.ParameterizedTest;
-import org.junit.jupiter.params.provider.*;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+import static org.junit.jupiter.api.Assertions.assertTimeoutPreemptively;
 
+import java.time.Duration;
 import java.util.stream.Stream;
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.Nested;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.Arguments;
+import org.junit.jupiter.params.provider.CsvSource;
+import org.junit.jupiter.params.provider.MethodSource;
 
 /**
  * Test class for HammingDistance calculator.
- * Tests various scenarios including:
- * - Valid string pairs with different Hamming distances
- * - Edge cases (empty strings, same strings)
- * - Invalid inputs (null values, unequal lengths)
- * - Special characters and Unicode strings
  */
-@DisplayName("Hamming Distance Calculator Tests")
 class HammingDistanceTest {
-    
+
     private static final String ERROR_MESSAGE_UNEQUAL_LENGTH = "String lengths must be equal";
     private static final String ERROR_MESSAGE_NULL_INPUT = "Input strings cannot be null";
 
     @Nested
-    @DisplayName("Valid Input Tests")
     class ValidInputTests {
-        
-        @ParameterizedTest(name = "Calculate distance between \"{0}\" and \"{1}\" = {2}")
+
+        @ParameterizedTest(name = "Calculate distance between {0} and {1} = {2}")
         @CsvSource({
-            // Basic cases
-            "'', '', 0",
-            "'java', 'java', 0",
-            "'karolin', 'kathrin', 3",
-            "'kathrin', 'kerstin', 4",
-            
-            // Binary strings
-            "'00000', '11111', 5",
-            "'10101', '10100', 1",
-            
-            // Special characters
-            "'hello!', 'hello.', 1",
-            "'@#$%^&', '@#$%^*', 1",
-            
-            // Unicode characters
-            "'über④⑤', 'uber45', 2",
-            "'münchen', 'munchen', 1"
+            ", , 0",
+            "java, java, 0",
+            "karolin, kathrin, 3",
+            "kathrin, kerstin, 4",
+            "00000, 11111, 5",
+            "10101, 10100, 1",
+            "hello!, hello., 1",
+            "@#$%^&, @#$%^*, 1"
         })
         void shouldCalculateHammingDistance(String s1, String s2, int expected) {
-            assertEquals(expected, HammingDistance.calculateHammingDistance(s1, s2),
-                    () -> String.format("Failed to calculate correct Hamming distance for '%s' and '%s'", s1, s2));
+            assertEquals(
+                expected,
+                HammingDistance.calculateHammingDistance(s1, s2),
+                String.format("Failed to calculate correct Hamming distance for '%s' and '%s'", s1, s2)
+            );
         }
 
         @Test
-        @DisplayName("Should handle maximum length strings")
         void shouldHandleMaximumLengthStrings() {
             String str1 = "a".repeat(1000);
             String str2 = "b".repeat(1000);
-            assertEquals(1000, HammingDistance.calculateHammingDistance(str1, str2),
-                    "Should correctly calculate distance for maximum length strings");
+            assertEquals(
+                1000,
+                HammingDistance.calculateHammingDistance(str1, str2),
+                "Should correctly calculate distance for maximum length strings"
+            );
         }
     }
 
     @Nested
-    @DisplayName("Invalid Input Tests")
     class InvalidInputTests {
-        
+
         @ParameterizedTest(name = "Test null input: first={0}, second={1}")
         @MethodSource("com.thealgorithms.strings.HammingDistanceTest#provideNullInputs")
         void shouldThrowExceptionForNullInputs(String input1, String input2) {
@@ -72,29 +67,34 @@ void shouldThrowExceptionForNullInputs(String input1, String input2) {
                 () -> HammingDistance.calculateHammingDistance(input1, input2),
                 "Should throw IllegalArgumentException for null inputs"
             );
-            assertEquals(ERROR_MESSAGE_NULL_INPUT, exception.getMessage(),
-                    "Exception message should match for null inputs");
+            assertEquals(
+                ERROR_MESSAGE_NULL_INPUT,
+                exception.getMessage(),
+                "Exception message should match for null inputs"
+            );
         }
 
-        @ParameterizedTest(name = "Test unequal lengths: \"{0}\" and \"{1}\"")
+        @ParameterizedTest(name = "Test unequal lengths: {0} and {1}")
         @CsvSource({
             "ab, abc",
             "a, aa",
             "hello, hi",
-            "'', a"
+            ", a"
         })
         void shouldThrowExceptionForUnequalLengths(String s1, String s2) {
             IllegalArgumentException exception = assertThrows(
                 IllegalArgumentException.class,
                 () -> HammingDistance.calculateHammingDistance(s1, s2),
                 "Should throw IllegalArgumentException for unequal length strings"
             );
-            assertEquals(ERROR_MESSAGE_UNEQUAL_LENGTH, exception.getMessage(),
-                    "Exception message should match for unequal lengths");
+            assertEquals(
+                ERROR_MESSAGE_UNEQUAL_LENGTH,
+                exception.getMessage(),
+                "Exception message should match for unequal lengths"
+            );
         }
     }
 
-    // Test data providers
     private static Stream<Arguments> provideNullInputs() {
         return Stream.of(
             Arguments.of(null, "abc"),
@@ -104,13 +104,12 @@ private static Stream<Arguments> provideNullInputs() {
     }
 
     @Test
-    @DisplayName("Performance test with large strings")
     void performanceTest() {
         String str1 = "a".repeat(10000) + "b".repeat(10000);
         String str2 = "a".repeat(10000) + "c".repeat(10000);
-        
+
         assertTimeoutPreemptively(
-            java.time.Duration.ofSeconds(1),
+            Duration.ofSeconds(1),
             () -> HammingDistance.calculateHammingDistance(str1, str2),
             "Should complete calculation within reasonable time"
         );